This invention relates generally to devices and methods for placing a sensor at a selected site within the body of a patient. More particularly, this invention relates to an improved and relatively simple insertion set for quick and easy transcutaneous placement of a flexible thin film sensor of the type used, for example, to obtain blood glucose readings.
In recent years, a variety of electrochemical sensors have been developed for a range of applications, including medical applications for detecting and/or quantifying specific agents in a patient's blood and other body fluids. As one example, glucose sensors have been developed for use in obtaining an indication of blood glucose levels in a diabetic patient. Such readings can be especially useful in monitoring and/or adjusting a treatment regimen which typically includes regular administration of insulin to the patient. In this regard, blood glucose readings are particularly useful in conjunction with semi-automated medication infusion pumps of the external type, as generally described in U.S. Pat. Nos. 4,562,751; 4,678,408; and 4,685,903; or automated implantable medication infusion pumps, as generally described in U.S. Pat. No. 4,573,994.
Relatively small and flexible electrochemical sensors have been developed for subcutaneous placement of sensor electrodes in direct contact with patient blood or other extracellular fluid, wherein such sensors can be used to obtain periodic readings over an extended period of time. In one form, flexible transcutaneous sensors are constructed in accordance with thin film mask techniques wherein an elongated sensor includes thin film conductive elements encased between flexible insulative layers of polyimide sheet or similar material. Such thin film sensors typically include exposed electrodes at a distal end for subcutaneous placement in direct contact with patient blood or the like, and exposed conductive contact pads at an externally located proximal end for convenient electrical connection with a suitable monitoring device. Such thin film sensors hold significant promise in patient monitoring applications, but unfortunately have been difficult to place transcutaneously with the sensor electrodes in direct contact with patient blood or other body fluid. Improved thin film sensors and related insertion sets are described in commonly assigned U.S. Pat. Nos. 5,390,671; 5,391,250; 5,482,473; 5,299,571; 5,586,553 and 5,568,806, which are incorporated by reference herein.
Notwithstanding the foregoing improvements in and to thin film electrochemical sensors and related transcutaneous insertion sets, there exists an on-going need for further improvements in such insertion sets particularly with respect to facilitated and cost efficient manufacture, improvements in quick and easy transcutaneous placement of the thin film sensor, and simplified attachment of the sensor to a conductive cable or the like for coupling of sensor signals to the associated monitoring device. The present invention fulfills these needs and provides further related advantages.